But it states that the E. Coli in Mutaflor is non pathogenic and has no properties of the harmful and mutated E. coli associated with food poisoning, illness, etc. E.Coli is naturally occurring in the gut, just like lactobacillus and bifidobacillus. Doses found in probiotics (unless taken in extremely high doses for a long time), I doubt will change the ecology of the gut where E. Coli is the predominant bacteria since there are trillions of them to begin with. The same argument can be applied to lactobacillus, that since Antibiotics wipe out good flora, supplementing with only lactobacillus will cause an imbalance. but given the amount and the nonpathogenic properties of probiotics, it merely assists and combats (or holds down the fort so to speak) until natural reinforcements arrive. Even with broad spectrum probiotics that contain 8-11 strains, and kefir, it simply cannot be a perfect match in number and diversity to the human gut since everything taken as a probiotic supplement is exogenous. Introducing good/nonpathogenic bacteria simply is equivalent to calling in the national guard until Local police forces can regroup, retrain, recover and hold their ground.